Instruction translation support method and information processing apparatus

ABSTRACT

A process includes receiving a table data set that represents mappings between a plurality of operand patterns indicating types of operands possibly included in a first instruction used in a first assembly language and a plurality of second instructions used in a second assembly language or a machine language corresponding to the second assembly language. The table data set maps two or more of the second instructions to each of the operand patterns. The process also includes generating, based on the table data set, a translation program used to translate first code written in the first assembly language into second code written in the second assembly language or the machine language. The translation program defines a process of determining an operand pattern of an instruction included in the first code and outputting two or more instructions of the second code according to the determined operand pattern.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2020-090112, filed on May 22, 2020, the entire contents of which are incorporated herein by reference.

FIELD

The embodiment discussed herein is related to an instruction translation support method and information processing apparatus.

BACKGROUND

It is sometimes the case that the user of an information processing system wishes to run an already existing program designed for a processor having an instruction set on a different processor having a different instruction set. For example, the user may wish to execute an existing program developed for small computers on a large-scale computer. On this occasion, if source code written in a high-level programming language is available as the existing program, the user compiles the source code using a compiler for the other processor to thereby generate an executable file for the other processor.

However, as for the existing program, sometimes its source code may be unavailable although an executable file designed for the original processor is ready for use. In that case, one conceivable approach is to translate assembly code for the original instruction set into assembly code or machine language code for the other instruction set. Assembly code is written in an assembly language, which is a low-level programming language. Instructions in assembly code correspond one-to-one with instructions in machine language code executable by a processor. A translation program for translating assembly code instructions is implemented for each pair of a translation source instruction set and a translation destination instruction set.

There is a proposed program translation apparatus for generating source code for a processor B from object code for a processor A. The proposed program translation apparatus replaces predefined instructions in the object code with intrinsic functions for the processor B.

Japanese Laid-open Patent Publication No. 2008-276735

A translation source instruction set sometimes includes combined instructions capable of representing complex operations, as typically seen in complex instruction set computer (CISC) architectures. The instruction lengths of such combined instructions may be variable. Even instructions of the same type, having the same mnemonic, may have different types of operands (parameters). The term “having different types of operands” here may cover the following cases, for example: varying in terms of the number of operands; varying in terms of the type of memory area specified by each operand; and varying in terms of the data length of the memory area specified by each operand.

On the other hand, a translation destination instruction set is sometimes formed of simple instructions capable of representing only simple operations, as typically seen in reduced instruction set computer (RISC) architectures. In translating a complex instruction set into a simple instruction set, it is sometimes difficult to represent computation equivalent to one instruction of the translation source instruction set using a single instruction of the translation destination instruction set. In that case, therefore, one instruction in original assembly code before translation may correspond to a combination of two or more instructions in the translated assembly or machine language code.

There remains a problem that implementation of a translation program for translating a complex instruction set into a simple one causes a developer intending to undertake the implementation to assume a heavy burden. The translation program, for example, analyzes not only mnemonics of instructions before translation but also operands of the instructions and outputs different combinations of translated instructions according to types of operands. Manually producing such a translation program imposes a great burden on the developer. In addition, with each expansion of the translation source instruction set, there is a need for manual modification of the translation program.

SUMMARY

According to one embodiment, there is provided a non-transitory computer-readable recording medium storing therein a computer program that causes a computer to execute a process including receiving a table data set that represents mappings between a plurality of operand patterns indicating types of operands possibly included in a first instruction used in a first assembly language and a plurality of second instructions used in a second assembly language or a machine language corresponding to the second assembly language, the table data set mapping two or more of the plurality of second instructions to each of the plurality of operand patterns; and generating, based on the table data set, a translation program used to translate first code written in the first assembly language into second code written in the second assembly language or the machine language, the translation program defining a process of determining an operand pattern of an instruction included in the first code and outputting two or more instructions of the second code according to the determined operand pattern.

The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an information processor according to a first embodiment;

FIG. 2 is a block diagram illustrating exemplary hardware of an information processor according to a second embodiment;

FIG. 3 illustrates an exemplary data flow of program porting;

FIG. 4 illustrates exemplary assembly codes before and after translation;

FIG. 5 illustrates an exemplary translation program;

FIG. 6 illustrates an exemplary pattern table;

FIG. 7 illustrates the exemplary pattern table, continuing from FIG. 6 ;

FIG. 8 illustrates the exemplary pattern table, continuing from FIG. 7 ;

FIG. 9 illustrates the exemplary pattern table, continuing from FIG. 8 ;

FIG. 10 illustrates an exemplary data flow of translation function generation;

FIG. 11 illustrates a first example of a translation function program;

FIG. 12 illustrates exemplary previews of the translation function program;

FIG. 13 illustrates a second example of the translation function program;

FIG. 14 illustrates exemplary simplification of operand conditions;

FIG. 15 illustrates the exemplary simplification of operand conditions, continuing from FIG. 14 ;

FIG. 16 is a block diagram illustrating exemplary functions of the information processor;

FIG. 17 is a flowchart illustrating a first exemplary procedure for the translation function generation;

FIG. 18 is a flowchart illustrating a second exemplary procedure for the translation function generation;

FIG. 19 is a flowchart illustrating the second exemplary procedure for the translation function generation, continuing from FIG. 18 ;

FIG. 20 is a flowchart illustrating the second exemplary procedure for the translation function generation, continuing from FIG. 19 ; and

FIG. 21 is a flowchart illustrating an exemplary procedure for executable file translation.

DESCRIPTION OF EMBODIMENTS

Several embodiments will be described below with reference to the accompanying drawings.

(a) First Embodiment

A first embodiment is described hereinafter.

FIG. 1 illustrates an information processor according to the first embodiment.

An information processor 10 of the first embodiment generates, from table data, a translation program for translating code written in an assembly language into code in a different assembly language or a machine language corresponding to the different assembly language. The generated translation program may be executed on the information processor 10 or a different information processor. The information processor 10 may be a client device or server device. The information processor 10 may be referred to, for example, as a computer or instruction translation support apparatus.

The information processor 10 includes a storing unit 11 and a processing unit 12. The storing unit 11 may be volatile semiconductor memory such as random access memory (RAM), or a non-volatile storage device such as a hard disk drive (HDD) or flash memory. The processing unit 12 is, for example, a processor such as a central processing unit (CPU), graphics processing unit (GPU), or digital signal processor (DSP). The processing unit 12 may include an electronic circuit designed for specific use, such as an application specific integrated circuit (ASIC) or field programmable gate array (FPGA). The processor executes programs stored in memory such as RAM (or in the storing unit 11). The term “multiprocessor”, or simply “processor”, may be used to refer to a set of multiple processors.

The storing unit 11 stores table data 13, which represents mappings between a plurality of operand patterns in a translation source assembly language and a plurality of instructions in a translation destination assembly language or machine language. Each assembly language is a low-level programming language that specifies assembly instructions corresponding one-to-one with machine language instructions executable by the processor. The translation source assembly language is compatible with a processor having a complex instruction set, like a so-called CISC processor. The translation destination assembly language or machine language is compatible with a processor having a relatively simple instruction set, like a so-called RISC processor.

Note however that the information processor 10 of the first embodiment does not specialize only in translating instructions of a CISC processor into those of a RISC processor. The first embodiment is also readily applicable to translating assembly code for the RISC processor into that for the CISC processor. Because an instruction set of the CISC processor contains instructions for simple operations similar to those of the RISC processor, it is possible to translate instructions of the RISC processor into those of the CISC processor for execution. On the other hand, the RISC processor also has single instructions each performing a complex operation in order to improve performance per clock cycle. In this case, it is possible to translate one instruction of the RISC processor into a plurality of instructions of the CISC processor.

The aforementioned operand patterns include operand patterns 13 a, 13 b, and 13 c. Each of the operand patterns 13 a, 13 b, and 13 c represents types of operands possibly included in an instruction X1 used in the translation source assembly language. The instruction X1 may be a combined instruction representing a complex operation, and may take different types of operands. The instruction X1 may vary, for example, in terms of the instruction length. The instruction X1 may vary, for example, in terms of the number of operands. The instruction X1 may vary, for example, in terms of the type of memory area specified by each operand. For instance, each operand indicates a register or main memory, or a different register type. The instruction X1 may vary, for example, in terms of the data length of data specified by each operand. For instance, each operand represents 128, 256, or 512 bits, and so on. The instruction X1 may be a vector operation instruction for running operations of the same kind on a plurality of unit data (words) in parallel.

In the example of FIG. 1 , the operand pattern 13 a indicates that a second operand specifies a register and the data length is 128 bits. The operand pattern 13 b indicates that the second operand specifies a register and the data length is 256 bits. The operand pattern 13 c indicates that the second operand specifies a memory area of the main memory and the data length is 128 bits.

The plurality of instructions used in the translation destination assembly language or machine language includes instructions Y1, Y2, Y3, Y4, and Y5. The instructions Y1, Y2, Y3, Y4, and Y5 are simple instructions each representing a relatively simple operation. For example, the instructions Y1, Y2, Y3, Y4, and Y5 have the same instruction length. For example, simple instructions representing operations between two data points do not include operands indicating the main memory. For example, operands in the instructions Y1, Y2, Y3, Y4, and Y5 have the same data length. For example, the instructions Y1, Y2, Y3, Y4, and Y5 do not include vector operation instructions.

Note here that it is difficult to represent an operation equivalent to one combined instruction using a single simple instruction. One combined instruction is often equivalent to a combination of two or more simple instructions. Therefore, the table data 13 maps, to each of the operand patterns 13 a, 13 b, and 13 c, two or more instructions amongst the instructions Y1, Y2, Y3, Y4, and Y5.

The table data 13 is matrix data, for example, including a plurality of rows corresponding to the operand patterns 13 a, 13 b, and 13 c and a plurality of columns corresponding to the instructions Y1, Y2, Y3, Y4, and Y5. One flag is located in a single cell at the intersection of one row with one column. The flag indicates whether an instruction corresponding to the column is used to translate the instruction X1 having an operand pattern corresponding to the row. For example, a flag equal to 1 is assigned when the instruction is used for the translation. The table data 13 is created, for example, by a developer who develops the translation program. The table data 13 may be created using spreadsheet software.

In the example of FIG. 1 , the instructions Y2 and Y5 are mapped to the operand pattern 13 a. Similarly, the instructions Y3 and Y5 are mapped to the operand pattern 13 b, and the instructions Y1, Y2, and Y5 are mapped to the operand pattern 13 c. The developer is able to define the aforementioned mappings by placing “1” in individual cells (1, 2), (1, 5), (2, 3), (2, 5), (3, 1), (3, 2), and (3, 5).

The processing unit 12 generates a translation program 14 based on the table data 13. The translation program 14 is software for translating code 15 written in the translation source assembly language into code 16 written in the translation destination assembly language or machine language. The code 15 is assembly code. The code 16 is assembly code or machine language code. The processing unit 12 generates, for example, source code of the translation program 14. The source code may be written in a high-level programming language such as C language.

The processing unit 12 analyzes the table data 13, and generates the translation program 14 such that instructions in the translation destination assembly language or machine language are output according to the mappings defined in the table data 13. The translation program 14 defines a process of determining an operand pattern of the instruction X1 included in the code 15 and outputting two or more instructions mapped to the determined operand pattern. The processing unit 12 may implement a determining process to identify a condition for outputting a combination of specific two or more instructions by scanning the table data 13 laterally and then determine if the identified condition is satisfied and an outputting process to output the combination of the two or more instructions. Alternatively, the processing unit 12 may implement a determining process to identify a condition for outputting one specific instruction by scanning the table data 13 vertically and then determine if the identified condition is satisfied and an outputting process to output the single instruction.

In the example of FIG. 1 , the code 15 includes the instruction X1, and operands included in the instruction X1 satisfy the operand pattern 13 c. According to the table data 13, the instructions Y1, Y2, and Y5 are mapped to the operand pattern 13 c. Therefore, the instructions Y1, Y2, and Y5 are inserted into the code 16. Note that the processing unit 12 may generate the translation program 14 such that two or more instructions mapped to one operand pattern are output sequentially column-wise from left to right across the table data 13. In this case, the table data 13 also represents the order of the translated instructions.

According to the information processor 10 of the first embodiment, the table data 13 is created, which represents mappings between the operand patterns 13 a, 13 b, and 13 c of the instruction X1 in the translation source assembly language and the instructions Y1, Y2, Y3, Y4, and Y5 in the translation destination assembly language or machine language. In the table data 13, a combination of two or more instructions is mapped to each operand pattern. Then, based on the table data 13, the translation program 14 for translating the instruction X1 is generated according to the mappings represented by the table data 13.

Herewith, the developer of the translation program 14 is able to efficiently define specifications of the translation program 14 using the table data 13. Creation of the table data 13 allows the developer to implement the translation program 14 without manually writing source code of the translation program 14. Therefore, the implementation burden of the translation program 14 is reduced. This is true especially when one combined instruction having various operands is translated into combinations of simple instructions according to the operands, as seen in the case of translating a CISC instruction set into a RISC instruction set.

In addition, if the translation source instruction set is expanded, the developer is able to implement the translation program 14 corresponding to the expanded instruction set by expanding the table data 13 without manually modifying the translation program 14.

Assume, for example, that the instruction set is expanded such that a mnemonic associated with the table data 13 is paired with a new operand pattern. In this case, a row corresponding to the new operand pattern is added to the table data 13, and flags are then simply assigned, within only the added row, to a combination of simple instructions corresponding to the operand pattern. If the operation of a translation target instruction is not covered by the existing instructions Y1, Y2, Y3, Y4, and Y5, one or more columns of translated instruction are simply added. In this case, there is no change in the mappings between the existing operands patterns 13 a, 13 b, and 13 c and the translated instructions (i.e., there is no need to make modifications in the rows corresponding to the operand patterns 13 a, 13 b, and 13 c). Therefore, even if description errors occur in adding a translation process for the new operand pattern, failures (translation errors) are observed only in the new operand pattern and have no effect on the translation processes corresponding to the existing operand patterns. That is, a check may be run independently on each operand pattern to see whether its translation process is correct, which also contributes to reduced implementation burden of the translation program 14.

(b) Second Embodiment

Next described is a second embodiment.

An information processor according to the second embodiment generates, from data in a table form, a translation program for translating assembly code of an instruction set (instruction set I) into assembly code of a different instruction set (instruction set A). In addition, the information processor of the second embodiment uses the generated translation program to carry out program porting to thereby translate machine language code of the instruction set I into that of the instruction set A. Note however that the generation of the translation program and the execution thereof may be performed by different information processors. The information processor of the second embodiment may be a client device or server device.

FIG. 2 is a block diagram illustrating exemplary hardware of an information processor according to the second embodiment.

An information processor 100 includes a CPU 101, a RAM 102, a HDD 103, an image interface 104, an input device interface 105, a media reader 106, and a communication interface 107. These units of the information processor 100 are individually connected to a bus. Note that the information processor 100 corresponds to the information processor 10 of the first embodiment. The CPU 101 corresponds to the processing unit 12 of the first embodiment. The RAM 102 or the HDD 103 corresponds to the storing unit 11 of the first embodiment.

The CPU 101 is a processor configured to execute program instructions. The CPU 101 reads out at least part of programs and data stored in the HDD 103, loads them into the RAM 102, and executes the loaded programs. Note that the CPU 101 may include two or more processor cores and the information processor 100 may include two or more processors. The term “multiprocessor”, or simply “processor”, may be used to refer to a set of processors.

The RAM 102 is volatile semiconductor memory for temporarily storing therein programs to be executed by the CPU 101 and data to be used by the CPU 101 for its computation. The information processor 100 may be provided with a different type of memory other than RAM, or may be provided with two or more memory devices.

The HDD 103 is a non-volatile storage device to store therein software programs, such as an operating system (OS), middleware, and application software, and various types of data. The information processor 100 may be provided with a different type of storage device, such as flash memory or a solid state drive (SSD), or may be provided with two or more storage devices.

The image interface 104 produces video images in accordance with drawing commands from the CPU 101 and displays them on a screen of a display device 111 coupled to the information processor 100. The display device ill may be any type of display, such as a cathode ray tube (CRT) display; a liquid crystal display (LCD); an organic electro-luminescence (OEL) display, or a projector. An output device, such as a printer, other than the display device 111 may also be connected to the information processor 100.

The input device interface 105 receives an input signal from an input device 112 connected to the information processor 100. Various types of input devices may be used as the input device 112, for example, a mouse, a touch panel, a touch-pad, or a keyboard. A plurality of types of input devices may be connected to the information processor 100.

The media reader 106 is a device for reading programs and data recorded on a storage medium 113. Various types of storage media may be used as the storage medium 113, for example, a magnetic disk such as a flexible disk (FD) or a HDD, an optical disk such as a compact disc (CD) or a digital versatile disc (DVD), and semiconductor memory. The media reader 106 copies the programs and data read out from the storage medium 113 to a different storage medium, for example, the RAM 102 or the HDD 103. The read programs are executed, for example, by the CPU 101. Note that the storage medium 113 may be a portable storage medium and used to distribute the programs and data. In addition, the storage medium 113 and the HDD 103 are sometimes referred to as computer-readable storage media.

The communication interface 107 is connected to a network 114 and communicates with different information processors via the network 114. The communication interface 107 may be a wired communication interface connected to a wired communication device, such as a switch or router, or may be a wireless communication interface connected to a wireless communication device, such as a base station or access point.

Next described is a program porting workflow for porting a user program developed for a CPU having the instruction set I to a CPU having the instruction set A. As for the user program, sometimes its source code written in a high-level programming language may be unavailable although an executable file for the port source CPU is ready for use. In that case, the executable file designed for the port source CPU is translated into an executable file for the port destination CPU.

FIG. 3 illustrates an exemplary data flow of program porting.

The information processor 100 acquires machine language code 131. The machine language code 131 is written in a machine language executable by the CPU having the instruction set I. The machine language code 131 is included in an executable file designed for the CPU having the instruction set I. The information processor 100 also acquires a reverse assembler 132. The reverse assembler 132 is software for translating machine language code of the instruction set I into assembly code of the instruction set I. The reverse assembler 132 is provided, for example, by the maker of the CPU.

The information processor 100 inputs the machine language code 131 to the reverse assembler 132 to translate the machine language code 131 into assembly code 133. The assembly code 133 is written in an assembly language of the instruction set I. The assembly language is a low-level programming language which represents types of machine language instructions and operands using strings to thereby enhance readability. There is a one-to-one correspondence between machine language instructions of the instruction set I and assembly instructions thereof.

The information processor 100 inputs the assembly code 133 to a translation program 134 to translate the assembly code 133 into assembly code 135. The assembly code 135 is written in an assembly language of the instruction set A. There is a one-to-one correspondence between machine language instructions of the instruction set A and assembly instructions thereof. The instruction set I corresponds to a CISC architecture while the instruction set A corresponds to a RISC architecture. Therefore, one instruction of the assembly code 133 may be translated into two or more instructions of the assembly code 135.

As will be described later, the information processor 100 generates in advance the translation program 134. A translation program is prepared for each combination of a translation source assembly language and a translation destination assembly language. The information processor 100 acquires an assembler 136. The assembler 136 is software for translating assembly code of the instruction set A into machine language code thereof. The assembler 136 is provided, for example, by the maker of the CPU having the instruction set A.

The information processor 100 inputs the assembly code 135 to the assembler 136 to thereby translate the assembly code 135 into machine language code 137. The machine language code 137 is written in a machine language executable by the CPU having the instruction set A. The machine language code 137 is included in an executable file designed for the CPU having the instruction set A. Herewith, the information processor 100 is able to translate the machine language code 131 of the instruction set I into the machine language code 137 of the instruction set A. Depending on the purposes, the translation program 134 need not be used in combination with the reverse assembler 132 and the assembler 136.

FIG. 4 illustrates exemplary assembly codes before and after translation.

Assembly code 141 is written in the assembly language of the instruction set I. The assembly code 141 corresponds to the aforementioned assembly code 133. Assembly code 142 is written in the assembly language of the instruction set A. The assembly code 142 corresponds to the aforementioned assembly code 135.

The instruction set I corresponds to a CISC architecture. Therefore, the assembly code 141 includes combined instructions representing complex operations.

Specifically, the assembly code 141 includes four instructions of mov, add, sub, and vpmaxsd. The first instruction of the assembly code 141 is to store 64-bit data in a register. The fourth instruction of the assembly code 141 is to compare operand #1 (xmm14) and operand #2 (xmm15) on a 32-bit word-by-word basis and store a larger word in operand #0 (xmm0). Each of operands #0, #1, and #2 is an operand representing a vector register having a data length of 128 bits. That is, the fourth instruction performs comparisons of each of four pairs of words and causes storage of four words.

On the other hand, the instruction set A corresponds to a RISC architecture. Therefore, the assembly code 142 includes only simple instructions representing simple operations. Specifically, the assembly code 142 includes a greater number of instructions than the assembly code 141, twenty one instructions. An instruction group 142 a including seven instructions corresponds to the first instruction of the assembly code 141. That is, an operation equivalent to the first instruction of the assembly code 141 is represented using the seven instructions of the instruction set A. This is because, in the instruction group 142 a, storage of a 64 bit-long word is implemented by dividing the word into four 16-bit words. An instruction group 142 b including twelve instructions corresponds to the fourth instruction of the assembly code 141. That is, an operation equivalent to the fourth instruction of the assembly code 141 is represented using the twelve instructions of the instruction set A.

In the assembly code 141, each operand denoted by rN (N is a natural number from 0 to 15) represents a general-purpose register with a register index N. In the assembly code 142, each operand denoted by xN (N is a natural number from 0 to 30) represents a general-purpose register with the register index N; the operand denoted by sp represents a stack pointer register; each operand denoted by pN (N is a natural number from 0 to 15) represents a predicate register (mask register) with the register index N; and each operand denoted by zN (N is a natural number from 0 to 31) represents a vector register with the register index N.

In addition, a mnemonic mov represents an instruction that copies data. A mnemonic add represents an instruction for data addition. A mnemonic sub represents an instruction for data subtraction. A mnemonic orr represents an instruction for a bitwise logical OR operation. A mnemonic str represents an instruction that reads data from memory and places it in a register. Bitwise not represents an instruction for a logical negation operation. A mnemonic cmpge represents an instruction that compares two vector registers word by word and places the comparison results in a predicate register. A mnemonic cmpgt represents an instruction that compares two vector registers word by word and places the comparison results in a predicate register. A mnemonic ldr represents an instruction that loads data stored in a register into memory.

In addition, [x24] indicates execution of the corresponding str or ldr instruction using an x24 register as an address register. “.s” indicates execution of the corresponding instruction, treating its vector or predicate register as a register for storing data represented by each word consisting of 32 bits. Each of “/m” and “/z” following a predicate register indicates that only words whose flags in the predicate register are enabled are subjected to the operation when the instruction is executed. “/m” indicates that words whose flags are disabled hold original values (i.e., values before the execution of the corresponding instruction). “/z” indicates that, for words whose flags are disabled, their values are cleared to zero after the execution of the corresponding instruction.

FIG. 5 illustrates an exemplary translation program.

The information processor 100 creates in advance a translation program 143 capable of translating the assembly code 141 into the assembly code 142. The translation program 143 corresponds to the aforementioned translation program 134.

Translation processing specified by the translation program 143 includes reading one instruction from translation source assembly code, extracting a mnemonic from the read instruction, and generating operand information by analyzing operands included in the read instruction. The mnemonic is a part of the instruction other than the operands and represents a type of the instruction, such as add, sub, or vpmaxsd. The operand information indicates the results of the operand analysis and represents characteristics of the operands. The operand information includes information on the number of operands, the type of each operand such as an immediate value, a register, or a main memory address, the data length of each operand, the presence or absence of options, and the like.

The translation processing specified by the translation program 143 calls a different translation function according to the extracted mnemonic. The translation program 143 includes a translation function for each mnemonic. For example, the translation program 143 includes a translation function translateADD corresponding to the mnemonic add; a translation function translateSUB corresponding to the mnemonic sub; and a translation function translateVPMAXSD corresponding to the mnemonic vpmaxsd. In calling a translation function, the translation processing designates the aforementioned operand information as parameters. Each translation function outputs a set of instructions according to the operand information given as its parameters. A different set of instructions may be output for different operand information even if the mnemonic is the same.

At this point, the question of how to implement each translation function becomes an issue. Because mappings between the types of operands and instructions to be output are sometimes complex, the developer bears a heavy burden if they need to manually write source code of each instruction function. In addition, there is a risk that errors are introduced to the translation function due to mistakes made by the developer while writing the source code. In view of these problems, the information processor 100 supports implementation of translation functions. The developer uses a pattern table to be described below to succinctly describe specifications of each translation function. Based on the pattern table written by the developer, the information processor 100 automatically generates source code of the translation function. Next described is an exemplary implementation of the translation function translateVPMAXSD amongst a plurality of translation functions.

FIG. 6 illustrates an exemplary pattern table.

A pattern table is prepared for each mnemonic. A pattern table 144 corresponds to the mnemonic vpmaxsd and represents specifications of the translation function translateVPMAXSD.

The pattern table 144 includes a plurality of rows and a plurality of columns. The developer is able to build the pattern table 144 using a user interface of spread sheet software. The pattern table 144 includes a title row for column names. In addition, the pattern table 144 includes thirty-one rows corresponding to thirty-one operand patterns.

In addition, the pattern table 144 includes column B for pattern numbers. The pattern table 144 also includes column E for formats of instructions of the instruction set I. The pattern table 144 further includes columns F, G, H, I, N, O, and P for seven operand conditions defining the operand patterns. The operand conditions are information included in the operand information which is parameters of the translation function translateVPMAXSD.

The pattern table 144 further includes thirty-six columns for thirty-six source code descriptions used to output instructions of the instruction set A. Each column for one source code description usually corresponds to a single instruction of the instruction set A. These thirty-six columns are arranged such that an appropriate sequence of instructions is obtained by outputting translated instructions indicated by some columns amongst the thirty-six columns in order from left to right across the columns of the pattern table 144. Therefore, the thirty-six columns include columns representing translated instructions of the same content.

FIG. 6 depicts a portion of the entire pattern table 144, identified by a subset of rows and a subset of columns. The subset of rows includes the title row and rows for pattern numbers #1 to #11. The subset of columns includes column B with pattern numbers, column E with formats of instructions, columns F, G, H, I, N, O, and P with operand conditions, and eight columns with translated instructions. That is, FIG. 6 represents the top-left section of the pattern table 144.

Colum F indicates types of operand #0. In the pattern table 144, REG0 is the only value included in column F. REG0 represents the first register. Colum G indicates types of operand #1. In the pattern table 144, REG1 is the only value included in column G. REG1 represents the second register. Colum H indicates types of operand #2. Each value in column H takes REG2 or MEM0. REG2 represents the third register. MEM0 represents a main memory area. Column I indicates types of operand #3. Each value in column I takes INVALID, REG3, or MEM0. INVALID represents that operand #3 does not exist. REG3 represents the fourth register. MEM0 represents the main memory area.

Column N indicates the data length (width in bits) of operand #0. In the pattern table 144, each value in column N takes 128, 256, or 512 bits. Column O indicates mask specifications. Each value in column O is blank, NO, ZERO, or MERG. Blank cells and NO indicate no masks. When no mask is used, all words in the vector register are designated as operation targets. Note that data of 128 bits includes four 32-bit long words, data of 256 bits includes eight words, and data of 512 bits includes sixteen words.

ZERO indicates application of a mask and zero filling. MERG indicates application of a mask and data coupling. When a mask is applied in an operation, only some of the words are designated as operation targets. When zero filling is applied in an operation, the bits of each word not specified are converted into a string of all 0's. When data coupling is applied in an operation, for each word not specified, a corresponding bit string previously existing in a register for storing operation results is copied into the word. Therefore, data coupling means to couple results of the previous operation and those of the latest operation.

Pre-translation instructions may include omission options k and/or z. The omission option k is an option to specify words to be targeted for the operation amongst a plurality of words. That is, a pre-translation instruction including no omission option k uses no mask. The omission option z is an option to indicate zero filling. A pre-translation instruction using a mask and including the omission option z indicates application of zero filling. A pre-translation instruction using a mask and not including the omission option z indicates data coupling. Therefore, the values in column O are determined based on the omission options k and z included in pre-translation instructions.

Column P indicates broadcasting specifications. Each value in column P is blank, 0 (no broadcasting), or 1 (broadcasting). In the case of no broadcasting, a plurality of words specified by operand #2 is compared one-to-one with a plurality of words specified by operand #3 (one-to-one comparison operation). In the case of broadcasting, a plurality of words specified by operand #2 is compared with one word specified by operand #3 (many-to-one comparison operation).

Each value in the thirty-six columns of the translated instructions is blank or 1. 0 may be used instead of blank. The values in the thirty-six columns are considered as one-bit flags. A blank in the cell where a row of one operand pattern and a column of one translated instruction intersect indicates that the translated instruction is not used to translate a pre-translation instruction having the operand pattern. On the other hand, 1 in the cell indicates that the translated instruction is used to translate a pre-translation instruction having the operand pattern. The developer is able to define specifications of the translation function translateVPMAXSD by entering 1's in appropriate cells of the pattern table 144.

FIG. 7 illustrates the exemplary pattern table, continuing from FIG. 6 .

FIG. 7 depicts a portion of the entire pattern table 144, identified by a subset of rows and a subset of columns. The subset of rows includes the title row and the rows for pattern numbers #1 to #11, as in the case of FIG. 6 . The subset of columns includes the remaining twenty-eight columns with translated instructions. That is, FIG. 7 represents the top-right section of the pattern table 144.

FIG. 8 illustrates the exemplary pattern table, continuing from FIG. 7 .

FIG. 8 depicts a portion of the entire pattern table 144, identified by a subset of rows and a subset of columns. The subset of rows includes rows for pattern numbers #12 to #31. The subset of columns includes column B with patter numbers, column E with formats of instructions, columns F, G, H, I, N, O, and P with the operand conditions, and the eight columns with the translated instructions, as in FIG. 6 . That is, FIG. 8 represents the bottom-left section of the pattern table 144.

FIG. 9 illustrates the exemplary pattern table, continuing from FIG. 8 .

FIG. 9 depicts a portion of the entire pattern table 144, identified by a subset of rows and a subset of columns. The subset of rows includes the rows for pattern numbers #12 to #31, as in the case of FIG. 8 . The subset of columns includes the remaining twenty-eight columns with the translated instructions, as in FIG. 7 . That is, FIG. 9 represents the bottom-right section of the pattern table 144.

FIG. 10 illustrates an exemplary data flow of translation function generation.

As stated previously, the developer creates a pattern table for each mnemonic. For example, the developer creates a pattern table 151 a representing specifications of the mnemonic vpmaxsd, a pattern table 151 b representing specifications of the mnemonic add, and a pattern table 151 c representing specifications of the mnemonic sub. The pattern table 151 a corresponds to the aforementioned pattern table 144. The information processor 100 receives the pattern tables 151 a, 151 b, and 151 c and inputs them to a generation tool 152 to thereby generate source codes 153 a, 153 b, and 153 c.

The generation tool 152 is software for generating source code of one translation function from each pattern table. Such source codes of translation functions are written in a high-level programming language such as C language. The source code 153 a is source code of the translation function translateVPMAXSD and generated from the pattern table 151 a. The source code 153 b is source code of the translation function translateADD and generated from the pattern table 151 b. The source code 153 c is source code of the translation function translateSUB and generated from the pattern table 151 c.

The information processor 100 compiles source code of a translation program body and the source codes 153 a, 153 b, and 153 c using a compiler tailored for the programming language. Herewith, the information processor 100 generates a translation program 154 including translation functions 154 a, 154 b, and 154 c. The translation function 154 a corresponds to the mnemonic vpmaxsd and is generated from the source code 153 a. The translation function 154 b corresponds to the mnemonic add and is generated from the source code 153 b. The translation function 154 c corresponds to the mnemonic sub and is generated from the source code 153 c.

After generating the translation program 154, the information processor 100 receives an assembly code 155 written in the assembly language of the instruction set I. The information processor 100 runs the translation program 154 with a designation of the assembly code 155 as input data, and generates an assembly code 156 written in the assembly language of the instruction set A. During execution of the translation program 154, the information processor 100 extracts each instruction from the assembly code 155 and calls a translation function corresponding to a mnemonic of the extracted instruction. The called translation function outputs an appropriate sequence of instructions based on the operand information.

Next described is how to generate a translation function from a pattern table.

Row-major order and column-major order are known as methods used to express mappings indicated by the pattern table 144 in a translation function program. In the row-major order, the translation function program includes thirty-one blocks corresponding to the thirty-one operand patterns. In the row-major order, the information processor 100 scans the pattern table 144 in a transverse direction and generates one block of the translation function program from each row of the pattern table 144. On the other hand, in the column-major order, the translation function program includes thirty-six blocks corresponding to the thirty-six source code descriptions. In the column-major order, the information processor 100 scans the pattern table 144 in a longitudinal direction and generates one block of the translation function program from each column of the pattern table 144. The row-major order is described first below.

FIG. 11 illustrates a first example of the translation function program.

A translation function program 145 is source code of the translation function translateVPMAXSD and generated from the pattern table 144 in the row-major order. The translation function program 145 includes blocks 145 a and 145 b. The block 145 a corresponds to the row of pattern number #1 in the pattern table 144. The block 145 b corresponds to the row of pattern number #2 in the pattern table 144. The translation function program 145 also includes blocks corresponding to pattern numbers #3 to #31.

The block 145 a includes a condition determination statement used to check whether the operand information, which is parameters, satisfies a specific execution condition. The execution condition of the block 145 a is to meet the operand conditions found in the row of pattern number #1 and columns F, G, H, I, and N of the pattern table 144. That is, the execution condition of the block 145 a is that operand #0 is REG0, operand #1 is REG1, operand #2 is REG2, operand #3 is INVALID, and the data length is 128 bits.

The block 145 a also includes twelve execution statements for outputting instructions of the instruction set A. In the row of pattern number #1 within the pattern table 144, a flag equal to 1 is set in each of columns U, AD, AG, AH, AK, AN, AO, AU, AY, BC, BJ, and BK. Therefore, the block 145 a includes twelve execution statements corresponding to the column names of these twelve columns. The twelve execution statements are arranged sequentially in order from left to right across the columns of the pattern table 144.

The block 145 b includes a condition determination statement used to check whether the operand information, which is parameters, satisfies a specific execution condition. The execution condition of the block 145 b is to meet the operand conditions found in the row of pattern number #2 and columns F, G, H, I, and N of the pattern table 144. That is, the execution condition of the block 145 b is that operand #0 is REG0, operand #1 is REG1, operand #2 is MEM0, operand #3 is INVALID, and the data length is 128 bits.

The block 145 b also includes sixteen execution statements for outputting instructions of the instruction set A. In the row of pattern number #2 within the pattern table 144, a flag equal to 1 is set in each of columns T, U, W, AA, AD, AG, AI, AK, AN, AU, AW, AZ, BC, BI, BJ, and BK. Therefore, the block 145 b includes sixteen execution statements corresponding to the column names of these sixteen columns. The sixteen execution statements are arranged sequentially in order from left to right across the columns of the pattern table 144.

Thus, the row-major order generates each block of the translation function program 145 from one row of the pattern table 144. The information processor 100 is able to generate thirty-one blocks corresponding to the thirty-one operand patterns independently of each other. The condition determination statement of each block is generated from the operand conditions of columns F, G, H, I, N, O, and P. The execution statements of each block are generated from the column names of columns in which “1” is written. The information processor 100 simply arranges the multiple column names, starting from the left and going toward the right of the pattern table 144.

FIG. 12 illustrates exemplary previews of the translation function program.

The information processor 100 may display a preview of each block of the translation function program 145 on the pattern table 144. In the example of FIG. 12 , previews of the blocks 145 a and 145 b are presented in column Q of the pattern table 144. The preview function may be implemented using a user interface of spreadsheet software. In that case, in response to an addition or deletion of a flag equal to 1 by the developer, the spreadsheet software updates a corresponding preview in column Q in real time. Herewith, the information processor 100 supports the developer in creating the pattern table 144. For example, the preview function is realized by writing the following mathematical expression in a cell Q1 of the pattern table 144.

=IF(T1< >“ ”, $T0 & CHAR(10), “ ”) & IF(U1< >“ ”, $U0 & CHAR(10), “ ”) & IF(W1< >“ ”, $W0 & CHAR(10), “ ”) & IF(Y1< >“ ”, $Y0 & CHAR(10), “ ”) & IF(Y1< >“ ”, $Y0 & CHAR(10), “ ”) . . . & IF(BK1< >“ ”, $BK0, “ ”).

If a value other than 0 is found in a cell at row 1 and column T, the aforementioned mathematical expression outputs, to the cell Q1, a string written in a cell at the leading row (title row) and column T together with a new-line character. If a value other than 0 is found in a cell at row 1 and column U, the mathematical expression also creates an additional output of a string written in a cell at the leading row and column U together with a new-line character to the cell Q1. Further, if a value other than 0 is found in a cell at row 1 and column BK, the mathematical expression also creates an additional output of a string written in a cell at the leading row and column BK to the cell Q1.

Next described is the column-major order. The developer may give, to the information processor 100, a designation of which one of the row-major and column-major order methods to be adopted in generating the translation function program.

FIG. 13 illustrates a second example of the translation function program.

A translation function program 146 is source code of the translation function translateVPMAXSD and generated from the pattern table 144 in the column-major order. The translation function program 146 includes blocks 146 a and 146 b. The block 146 a corresponds to column T of the pattern table 144. The block 146 b corresponds to column U of the pattern table 144. The translation function program 146 also includes blocks corresponding to the remaining thirty-four columns.

The block 146 a includes a condition determination statement used to check whether the operand information, which is parameters, satisfies a specific execution condition. The execution condition of the block 146 a is that the operand information falls into any one of twenty-six operand patterns having “1” in column T amongst the thirty-one operand patterns of the pattern table 144. Operand conditions of the twenty-six operand patterns are linked by logical ORs. The block 146 a also includes one execution statement corresponding to column T. The execution statement of the block 146 a is the column name of column T.

The block 146 b includes a condition determination statement used to check whether the operand information, which is parameters, satisfies a specific execution condition. The execution condition of the block 146 b is that the operand information falls into any one of twenty-three operand patterns having “1” in column U amongst the thirty-one operand patterns of the pattern table 144. Operand conditions of the twenty-three operand patterns are linked by logical ORs. The block 146 b also includes one execution statement corresponding to column U. The execution statement of the block 146 b is the column name of column U.

Thus, the column-major order generates each block of the translation function program 146 from one column of the pattern table 144. The information processor 100 is able to generate thirty-six blocks corresponding to the thirty-six columns independently of each other. The information processor 100 arranges, in the translation function program 146, the thirty-six blocks sequentially column-wise, starting from the left and going toward the right of the pattern table 144.

In the column-major order, simply linking operand conditions of operand patterns having a flag equal to 1 by logical ORs significantly increases the size of the condition determination statement of each block. Note however that the condition determination statement of each block includes redundant comparison expressions, which may be simplified to make the condition determination statement sufficiently short. On the other hand, the column-major order includes only one execution statement in each block, and thus prevents repetition of the same execution statements in the translation function program. Therefore, compared to the row-major order, the column-major order is able to generate a high-speed translation function program by simplifying the condition determination statements to thereby reduce the size of the translation function program.

Simplification of the condition determination statements may be automatically performed by a compiler during optimization processing when the compiler compiles source code of the translation function program 146. Alternatively, the information processor 100 may apply logic compression for simplifying logic expressions to the condition determination statements by use of a formula manipulation library in generating the source code of the translation function program 146. Alternatively, the information processor 100 may simplify the condition determination statements in an explicit procedure described below.

FIG. 14 illustrates exemplary simplification of operand conditions.

First, based on the pattern table 144, the information processor 100 calculates the number of columns C by counting columns representing operand conditions, and calculates the number of rows R by counting rows representing operand patterns. The information processor 100 generates an array 161 (array pattern) with size of C×R and an array 162 (array flag) with size of C.

Next, the information processor 100 scans each of columns F, G, H, I, N, O, and P representing the operand conditions, then enumerates one or more unique values for each column and registers them in the array 161. In each element (0, *) in the array 161, a unique value in column F is registered. Specifically, an element (0, 0)=REG0. In each element (1, *), a unique value in column G is registered. Specifically, an element (1, 0)=REG1. In each element (2, *), a unique value in column H is registered. Specifically, an element (2, 0)=REG2 and an element (2, 1)=MEM0.

Similarly, in each element (3, *), a unique value in column I is registered. Specifically, an element (3, 0)=INVALID, an element (3, 1)=REG3, and an element (3, 2)=MEM0. In each element (4, *), a unique value in column N is registered. Specifically, an element (4, 0)=128, an element (4, 1)=256, and an element (4, 2)=512. In each element (5, *), a unique value in column O is registered. Specifically, an element (5, 0)=NO, an element (5, 1)=ZERO, and an element (5, 2)=MERG. In each element (6, *), a unique value in column P is registered. Specifically, an element (6, 0)=0 and an element (6, 1)=1.

Next, the information processor 100 detects, on the array 161, columns each including only one unique value amongst columns F, G, H, I, N, O, and P representing the operand conditions. Because operand conditions having only one unique value do not affect the selection of an operand pattern, they may be ignored. The information processor 100 is able to detect columns including only one unique value by searching the array 161 for each element number in the first dimension, whose element (*, 1) is blank. In the example of FIG. 14 , amongst columns F, G, H, I, N, O, and P, columns F and G are columns each including only one unique value. The information processor 100 updates, to false, elements in the array 162, corresponding to the detected columns. Note that each element in the array 162 has an initial value of true.

Next, the information processor 100 extracts, from the array 162, element numbers whose elements have a value of true, and then extracts, from the array 161, elements whose element numbers in the first dimension match those extracted from the array 162. The information processor 100 generates a proposition of “column symbol=value” from each element extracted from the array 161 and registers it in an array 163 (array proposition).

An element (2, 0) in the array 163 is a proposition that “the value of column H is REG2”. An element (2, 1) is a proposition that “the value of column H is MEM0”. An element (3, 0) is a proposition that “the value of column I is INVALID”. An element (3, 1) is a proposition that “the value of column I is REG3”. An element (3, 2) is a proposition that “the value of column I is MEM0”. An element (4, 0) is a proposition that “the value of column N is 128”. An element (4, 1) is a proposition that “the value of column N is 256”. An element (4, 2) is a proposition that “the value of column N is 512”. An element (5, 0) is a proposition that “the value of column O is NO”. An element (5, 1) is a proposition that “the value of column O is ZERO”. An element (5, 2) is a proposition that “the value of column O is MERG”. An element (6, 0) is a proposition that “the value of column P is 0”. An element (6, 1) is a proposition that “the value of column P is 1”.

Next, the information processor 100 replaces, amongst columns F, G, H, I, N, O, and P of the pattern table 144, values in columns H, I, N, O, and P for which the propositions are defined with proposition symbols each indicating a corresponding element in the array 163. In the example of FIG. 14 , each element of the array 163 is denoted by P[*][*]. Herewith, a pattern table 164 is generated.

As for pattern number #1 in the pattern table 164, the values of columns H, I, and N are replaced with P[2][0], P[3][0], and P[4][0]. As for pattern number #2, the values of columns H, I, and N are replaced with P[2][1], P[3][0], and P[4][0]. As for pattern number #3, the values of columns H, I, and N are replaced with P[2][0], P[3][0], and P[4][1]. As for pattern number #4, the values of columns H, I, and N are replaced with P[2][1], P[3][0], and P[4][1].

FIG. 15 illustrates the exemplary simplification of operand conditions, continuing from FIG. 14 .

Next, the information processor 100 generates, based on the pattern table 164, a conjunctive proposition for each of columns T to BK representing translated instructions. At this time, the information processor 100 first generates a conjunctive proposition for each row of the pattern table 164 by connecting the proposition symbols in columns H, I, N, O, and P by logical ANDs. Then, the information processor 100 generates a conjunctive proposition of each column by further connecting, by logical ORs, conjunctive propositions of rows each having a value of “1”. Subsequently, the information processor 100 simplifies the conjunctive proposition with proposition symbols using a logical compression algorithm.

For ease of explanation, assume here that the pattern table 164 includes only four rows with pattern numbers #1 to #4 and columns B, H, I, N, and T. In this case, the information processor 100 generates a conjunctive proposition of P[2][0] and P[3][0] and P[4][0] for pattern number #1. The information processor 100 also generates a conjunctive proposition of P[2][1] and P[3][0] and P[4][0] for pattern number #2. The information processor 100 generates a conjunctive proposition of P[2][0] and P[3][0] and P[4][1] for pattern number #3. The information processor 100 also generates a conjunctive proposition of P[2][1] and P[3][0] and P[4][1] for pattern number #4.

In column T, a flag equal to 1 is set for pattern numbers #2 and #4. Therefore, the information processor 100 connects the conjunctive propositions of pattern numbers #2 and #4 by a logical OR to thereby generate a conjunctive proposition 165 of column T. The conjunctive proposition 165 is P[2][1] and P[3][0] and P[4][0] or P[2][1] and P[3][0] and P[4][1].

The information processor 100 simplifies the conjunctive proposition 165 to generate a conjunction proposition 166. Note here that only the proposition P[3][0] appears in column I of the pattern table 164 (i.e., for this translation target mnemonic, only operand patterns with the proposition P[3][0] being always true are input as those associated with column I). For this reason, the proposition P[3][0] does not affect the conclusion of the conjunctive proposition 165 and may therefore be deleted. In addition, only the propositions P[4][0] and P[4][1] appear in column N of the pattern table 164. Because both the propositions P[4][0] and P[4][1] appear in the conjunctive proposition 165, the propositions P[4][0] and P[4][1] may therefore be deleted. As a result, a simplified conjunctive proposition 166 is P[2][1].

The information processor 100 puts the proposition symbol included in the conjunctive proposition 166 back to the original proposition format. Herewith, the conjunctive proposition 166 is converted into “the value of column H is MEM0”. The information processor 100 translates each proposition into a conditional expression in the form of “column name==value”. Herewith, a condition determination statement of opName2==MEM0 is generated. The information processor 100 generates a block 167 including the condition determination statement and an execution statement corresponding to the column name of column T. In the above-described manner, the information processor 100 is able to generate a translation function program in the column-major order.

Next described are functions and procedures of the information processor 100.

FIG. 16 is a block diagram illustrating exemplary functions of an information processor.

The information processor 100 includes a table storing unit 121, a translation function storing unit 122, and an executable file storing unit 123. These storing units are implemented using a storage area secured, for example, in the RAM 102 or the HDD 103. The information processor 100 also includes a table editing unit 124, a translation function generating unit 125, and an executable file translating unit 126. These processing units are implemented, for example, using programs executed by the CPU 101.

The table storing unit 121 stores pattern tables each corresponding to a mnemonic included in the instruction set I. The translation function storing unit 122 stores source codes of translation functions each corresponding a mnemonic included in the instruction set I. The translation function storing unit 122 also stores source code of the translation program body.

In addition, the translation function storing unit 122 stores a compiler for compiling these source codes. The translation function storing unit 122 also stores a compiled translation program. The translation function storing unit 122 further stores a reverse assembler for the instruction set I and an assembler for the instruction set A. The executable file storing unit 123 stores an executable file of the pre-translation instruction set I and an executable file of the post-translation instruction set A.

The table editing unit 124 displays a pattern table stored in the table storing unit 121 on a screen of the display device 111. The table editing unit 124 receives an input operation performed on the input device 112, then updates the pattern table according to the input operation, and stores the updated pattern table in the table storing unit 121. The table editing unit 124 may be implemented using spreadsheet software.

The translation function generating unit 125 reads a pattern table corresponding to each mnemonic from the table storing unit 121, then generates source code of a translation function corresponding to the mnemonic, and stores the generated source code in the translation function storing unit 122. The translation function generating unit 125 generates the source codes of the translation functions using either one of the aforementioned row-major and column-major orders. The translation function generating unit 125 may receive an input operation indicating the selection of the row-major or column-major order from the developer.

In addition, the translation function generating unit 125 generates source code of the translation program body used to call a translation function corresponding to each mnemonic, and stores the generated source code in the translation function storing unit 122. The translation function generating unit 125 generates a compiled translation program by inputting the source code of the translation program body and the source codes of the translation functions to the compiler, and stores the compiled translation program in the translation function storing unit 122.

The executable file translating unit 126 receives an input operation specifying the executable file of the translation target instruction set I. In response, the executable file translating unit 126 reads the executable file of the instruction set I from the executable file storing unit 123 and generates assembly code of the instruction set I by inputting the read executable file to the reverse assembler. The executable file translating unit 126 reads the compiled translation program from the translation function storing unit 122, runs the translation program with a designation of the assembly code of the instruction set I as input data to thereby generate assembly code of the instruction set A. The executable file translation unit 126 generates an executable file of the instruction set A by inputting the assembly code of the instruction set A to the assembler, and stores the generated executable file of the instruction set A in the executable file storing unit 123.

FIG. 17 is a flowchart illustrating a first exemplary procedure for translation function generation.

The generation of a translation function described below uses the row-major order.

(Step S10) The translation function generating unit 125 selects, from a pattern table, one row representing an operand pattern. The row selected here is denoted by row i (i is an integer greater than or equal to 1). The translation function generation unit 125 outputs a string of “if(”. Note however that, in the case of selecting a row for the second time and onward, the translation function generating unit 125 outputs a string of “else if(” instead.

(Step S11) The translation function generating unit 125 selects one column representing an operand condition from the pattern table. The column selected here is denoted by column j (j is an integer greater than or equal to 1).

(Step S12) The translation function generating unit 125 determines whether a value is set in cell (i, j) of the pattern table. If a value is set in cell (i, j), the translation function generating unit 125 moves to step S13, and otherwise moves to step S14.

(Step S13) The translation function generating unit 125 extracts, from the pattern table, the column name written in the title row of column j and the value of cell (i, j). The translation function generating unit 125 outputs a string of “[column name]==[value of cell(i, j)]&&”.

(Step S14) The translation function generating unit 125 determines whether all columns each representing an operand condition have been selected in step S11. If all the columns representing operand conditions have been selected, the translation function generating unit 125 moves to step S15, and otherwise returns to step S11.

(Step S15) The translation function generating unit 125 outputs a string of “norue){”.

(Step S16) The translation function generating unit 125 selects one column representing a translated instruction from the pattern table. The column selected here is denoted by column k (k is an integer greater than or equal to 1).

(Step S17) The translation function generating unit 125 determines whether the value of cell (i, k) in the pattern table is 1. If the value of cell (i, k) is 1, the translation function generating unit 125 moves to step S18. If cell (i, k) is blank, the translation function generating unit 125 moves to step S19.

(Step S18) The translation function generating unit 125 extracts the column name written in the title row of column k from the pattern table. The column name corresponds to an execution statement of source code for generating an instruction of the instruction set A. The translation function generating unit 125 outputs the extracted column name.

(Step S19) The translation function generating unit 125 determines whether all columns each representing a translated instruction have been selected in step S16. If all the columns representing translated instructions have been selected, the translation function generating unit 125 moves to step S20, and otherwise returns to step S16.

(Step S20) The translation function generating unit 125 outputs a string of “}”.

(Step S21) The translation function generating unit 125 determines whether all rows each representing an operand pattern have been selected in step S10. If all the rows representing operand patterns have been selected, the translation function generating unit 125 ends the translation function generation, and otherwise returns to step S10.

FIG. 18 is a flowchart illustrating a second exemplary procedure for the translation function generation.

The generation of a translation function described below uses the column-major order.

(Step S30) The translation function generating unit 125 calculates the number of rows R by counting rows representing operand patterns in a pattern table. The translation function generating unit 125 also calculates the number of columns C by counting columns representing operand conditions in the pattern table.

(Step S31) The translation function generating unit 125 generates an array flag of size C and initializes each element of the array flag to true. The translation function generating unit 125 also generates an array pattern of size C×R, and initializes each element of the array pattern to blank. Note that each element number of the array flag is an integer greater than or equal to 0 and less than or equal to (C−1). In the array pattern, numbers in the first dimension are integers greater than or equal to 0 and less than or equal to (C−1), and numbers in the second dimension are integers greater than or equal to 0 and less than or equal to (R−1).

(Step S32) The translation function generating unit 125 selects one column representing an operand condition from the pattern table. The column selected here is denoted by column j.

(Step S33) The translation function generating unit 125 scans column j of the pattern table, and detects one or more unique values in column j and then stores each of them in pattern [j][*]. The unique values are those obtained after eliminating duplication amongst values present in column j. The notation pattern [j][*] indicates, amongst elements of the array pattern, each element whose number in the first dimension is j. In filling pattern [j][*] with unique values, the translation function generating unit 125 gives priority to an element whose number in the second dimension is smaller.

(Step S34) The translation function generating unit 125 determines whether all columns each representing an operand condition have been selected in step S32. If all the columns representing operand conditions have been selected, the translation function generating unit 125 moves to step S35, and otherwise returns to step S32.

(Step S35) The translation function generating unit 125 selects one column representing an operand condition from the pattern table. The column selected here is denoted by column j.

(Step S36) The translation function generating unit 125 determines whether column j contains only one unique value based on the array pattern. For example, the translation function generating unit 125 determines whether pattern [j][1] is blank. If pattern [j][1] is blank, column j contains only one unique value. If pattern [j][1] is not blank, column j contains two or more unique values. The translation function generating unit 125 moves to step S37 if column j contains only one unique value, and moves to step S38 if column j contains two or more unique values.

(Step S37) The translation function generating unit 125 updates flag[j] with false.

(Step S38) The translation function generating unit 125 determines whether all columns each representing an operand condition have been selected in step S35. If all the columns representing operand conditions have been selected, the translation function generating unit 125 moves to step S39, and otherwise returns to step S35.

FIG. 19 is a flowchart illustrating the second exemplary procedure for the translation function generation, continuing from FIG. 18 .

(Step S39) The translation function generating unit 125 selects one column representing an operand condition from the pattern table. The column selected here is denoted by column j.

(Step S40) The translation function generating unit 125 determines whether flag[j] is true. If flag[j] is true, the translation function generating unit 125 moves to step S41. If flag[j] is false, the translation function generating unit 125 moves to step S42.

(Step S41) The translation function generating unit 125 identifies, for each non-blank pattern [j][*], the column symbol representing column j and a condition value stored in pattern[j][*], and generates a proposition that “the value of [column symbol] is [condition value]”. The translation function generating unit 125 stores the generated proposition in proposition[j][*]. Numbers in the second dimension of proposition[j][*] are the same as those of pattern [j][*].

(Step S42) The translation function generating unit 125 determines whether all columns each representing an operand condition have been selected in step S39. If all the columns representing operand conditions have been selected, the translation function generating unit 125 moves to step S43, and otherwise returns to step S39.

(Step S43) The translation function generating unit 125 selects one column representing an operand condition from the pattern table. The column selected here is denoted by column j.

(Step S44) The translation function generating unit 125 determines whether flag[j] is true. The translation function generating unit 125 moves to step S45 if flag[j] is true, and moves to step S46 if flag[j] is false.

(Step S45) The translation function generating unit 125 replaces the value of cell (i, j) in the pattern table with a proposition symbol representing the proposition in proposition [j][*].

(Step S46) The translation function generating unit 125 determines whether all columns each representing an operand condition have been selected in step S43. If all the columns representing operand conditions have been selected, the translation function generating unit 125 moves to step S47, and otherwise returns to step S43.

FIG. 20 is a flowchart illustrating the second exemplary procedure for the translation function generation, continuing from FIG. 19 .

(Step S47) The translation function generating unit 125 selects one column representing a translated instruction from the pattern table. The column selected here is denoted by column k. The translation function generating unit 125 also defines a string variable called conjunctive proposition and then initializes the conjunctive proposition to blank.

(Step S48) The translation function generating unit 125 selects one row representing an operand pattern from the pattern table. The row selected here is denoted by row i. The translation function generating unit 125 also defines a string variable called tmp conjunctive proposition and then initializes the tmp conjunctive proposition to blank.

(Step S49) The translation function generating unit 125 determines whether the value of cell (i, k) in the pattern table is 1. The translation function generating unit 125 moves to step S50 if the value of cell (i, k) is 1, and moves to step S55 if cell (i, k) is blank.

(Step S50) The translation function generating unit 125 selects one column representing an operand condition from the pattern table. The column selected here is denoted by column j.

(Step S51) The translation function generating unit 125 determines whether flag[j] is true. The translation function generating unit 125 moves to step S52 if flag[j] is true, and moves to step S53 if flag[j] is false.

(Step S52) The translation function generating unit 125 extracts the value of cell (i, j) from the pattern table, and generates a new proposition which is a logical AND of the temp conjunctive proposition and the value of cell (i, j). The translation function generating unit 125 plugs the generated proposition into the temp conjunctive proposition.

(Step S53) The translation function generating unit 125 determines whether all columns each representing an operand condition have been selected in step S50. If all the columns representing operand conditions have been selected, the translation function generating unit 125 moves to step S54, and otherwise returns to step S50.

(Step S54) The translation function generating unit 125 generates a new proposition which is a logical OR of the conjunctive proposition and the temp conjunctive proposition. The translation function generating unit 125 plugs the generated proposition into the conjunctive proposition.

(Step S55) The translation function generating unit 125 determines whether all rows each representing an operand pattern have been selected in step S48. If all the rows representing operand patterns have been selected, the translation function generating unit 125 moves to step S56, and otherwise returns to step S48.

(Step S56) The translation function generating unit 125 simplifies the conjunctive proposition. The translation function generating unit 125 may use a formula manipulation library implementing a logical compression algorithm.

(Step S57) The translation function generating unit 125 extracts the column name written in the title row of column k from the pattern table. Then, the translation function generating unit 125 outputs a string of “if ([conjunction proposition]) {(column name)}”.

(Step S58) The translation function generating unit 125 determines whether all columns each representing a translated instruction have been selected in step S47. If all the columns representing translated instructions have been selected, the translation function generating unit 125 ends the translation function generation, and otherwise returns to step S47.

FIG. 21 is a flowchart illustrating an exemplary procedure for executable file translation.

(Step S60) The executable file translating unit 126 reads the executable file of the instruction set I designated as a translation target from the executable file storing unit 123.

(Step S61) The executable file translating unit 126 uses a reverse assembler for the instruction set I to thereby generate assembly code of the instruction set I from the executable file of the instruction set I.

(Step S62) The executable file translating unit 126 selects one instruction from the assembly code generated in step S61. The instruction selected here is denoted by an instruction I.

(Step S63) The executable file translating unit 126 extracts a mnemonic from the instruction I. The mnemonic is a string representing an instruction type, such as add or sub.

(Step S64) The executable file translating unit 126 extracts operands from the instruction I and analyzes them. The operands are strings following the mnemonic. The executable file translating unit 126 generates operand information on characteristics of the operands, such as the number of operands and the data length.

(Step S65) The executable file translating unit 126 designates the operand information generated in step S64 as parameters and calls a translation function corresponding to the mnemonic extracted in step S63. The executable file translating unit 126 acquires an instruction of the instruction set A as a return value of the translation function. The instruction acquired here is denoted by an instruction A. Note that the instruction A acquired here may be composed of only one instruction or two or more instructions.

(Step S66) The executable file translating unit 126 adds the instruction A acquired in step S65 to the end of assembly code of the translated instruction set A.

(Step S67) The executable file translating unit 126 determines whether all instructions each included in the assembly code of the instruction set I have been selected in step S62. If all the instructions have been selected, the executable file translating unit 126 moves to step S68, and otherwise returns to step S62.

(Step S68) The executable file translating unit 126 generates an executable file of the instruction set A from the assembly code of the instruction set A using the assembler designed for the instruction set A. The executable file translating unit 126 stores the executable file of the instruction set A in the executable file storing unit 123.

According to the information processor 100 of the second embodiment, an executable file designed for a processor having the instruction set I is translated into an executable file for a processor having the instruction set A. Therefore, even if source code of an already existing program is not available, the existing program is made reusable in different computation environments. In addition, a translation program for translating assembly code is automatically generated from pattern tables created by the developer. Therefore, the implementation burden on the developer is reduced compared to the case where the developer manually implements the translation program. Further, there is a reduced risk of introducing errors into the translation program resulting from operational errors.

Especially, there is a complexity about translation from a CISC instruction set into a RISC instruction set because one pre-translation instruction is translated into different sets of instructions according to operand types. In this regard, the auto-generation of the translation program reduces the implementation burden on the developer. In addition, each pattern table includes rows corresponding to operand patterns and columns corresponding to translated instructions, and has a user interface including entry cells for flags at the intersections of the rows and the columns. Further, multiple columns corresponding to multiple translated instructions are arranged sequentially from left to right in the order of execution. Therefore, the developer is able to efficiently define the specifications of the translation function simply by entering flags, such as “l's”, in the pattern table.

When the translation source instruction set is expanded, the developer is able to modify the translation program by adding rows for newly created operand patterns to a corresponding pattern table. Therefore, the work burden on the developer is reduced compared to the case where the developer manually modifies the translation program. In addition, new entries to the rows corresponding to the new operand patterns have no influence on specifications of the translation function, related to already existing operand patterns. Therefore, there is a reduced risk of causing errors in the translation program associated with the modification. In addition, the developer is able to build the pattern table progressively, starting with operand patterns whose specifications have been established.

In addition, by the use of a function for previewing the pattern table, the developer is able to edit the pattern table while checking in real time the source code of the translation program being produced. Herewith, the work efficiency of the developer is improved. Further, adoption of the column-major order and simplification of the condition determination statements allow the translation program to be efficient and reduced in size.

According to an aspect, it is possible to reduce the implementation burden of a translation program used to translate instructions between different instruction sets.

All examples and conditional language provided herein are intended for the pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A non-transitory computer-readable recording medium storing therein a computer program that causes a computer to execute a process comprising: receiving a table data set that represents mappings between a plurality of operand patterns and a plurality of second instructions, the plurality of operand patterns indicating types of operands possibly included in a first instruction used in a first assembly language, the plurality of second instructions being used in a second assembly language or a machine language corresponding to the second assembly language, the table data set mapping two or more of the plurality of second instructions to each of the plurality of operand patterns, the plurality of operand patterns including a first operand pattern and a second operand pattern, the first operand pattern designating a first register having a first bit length, the second operand pattern designating a second register having a second bit length different from the first bit length; and generating, based on the table data set, a translation program used to translate first code written in the first assembly language into second code written in the second assembly language or the machine language, the translation program defining a process of determining an operand pattern of an instruction included in the first code and outputting two or more instructions of the second code according to the determined operand pattern.
 2. The non-transitory computer-readable recording medium according to claim 1, wherein: the table data set is data in a form of a matrix including a plurality of rows representing the plurality of operand patterns and a plurality of columns representing the plurality of second instructions, and in the table data set, a flag is placed at an intersection of one row corresponding to one operand pattern and one column corresponding to one second instruction, the flag indicating whether the one second instruction is used to translate the first instruction having the one operand pattern.
 3. The non-transitory computer-readable recording medium according to claim 2, wherein: in the table data set, two or more flags are placed in the one row, each of which indicates that a corresponding second instruction is used to translate the first instruction having the one operand pattern, and the translation program is generated such that second instructions corresponding to two or more columns in which the two or more flags are placed are output sequentially column-wise from left to right across the table data set.
 4. The non-transitory computer-readable recording medium according to claim 2, wherein: the translation program includes a plurality of program blocks corresponding to the plurality of operand patterns, and each of the plurality of program blocks defines a process of outputting the two or more of the plurality of second instructions responsive to satisfaction of a specific condition, and the generating includes determining the specific condition of each of the plurality of program blocks by scanning flags placed in each of the plurality of rows.
 5. The non-transitory computer-readable recording medium according to claim 2, wherein: the translation program includes a plurality of program blocks corresponding to the plurality of second instructions, and each of the plurality of program blocks defines a process of outputting a second instruction corresponding to the program block responsive to satisfaction of a specific condition, and the generating includes determining the specific condition of each of the plurality of program blocks by scanning flags placed in each of the plurality of columns.
 6. The non-transitory computer-readable recording medium according to claim 1, wherein: the plurality of operand patterns differs in at least one of counts of the operands, types of memory areas designated by the operands, and data lengths of the operands.
 7. The non-transitory computer-readable recording medium according to claim 1, wherein: the receiving includes receiving a plurality of table data sets corresponding to a plurality of first instructions used in the first assembly language, and the generating includes generating, based on the plurality of table data sets, the translation program including a plurality of translation functions corresponding to the plurality of first instructions.
 8. The non-transitory computer-readable recording medium according to claim 1, wherein: the process further includes receiving the first code and running the generated translation program to translate the first code into the second code.
 9. An instruction translation support method comprising: receiving, by a processor, a table data set that represents mappings between a plurality of operand patterns and a plurality of second instructions, the plurality of operand patterns indicating types of operands possibly included in a first instruction used in a first assembly language, the plurality of second instructions being used in a second assembly language or a machine language corresponding to the second assembly language, the table data set mapping two or more of the plurality of second instructions to each of the plurality of operand patterns, the plurality of operand patterns including a first operand pattern and a second operand pattern, the first operand pattern designating a first register having a first bit length, the second operand pattern designating a second register having a second bit length different from the first bit length; and generating, by the processor, based on the table data set, a translation program used to translate first code written in the first assembly language into second code written in the second assembly language or the machine language, the translation program defining a process of determining an operand pattern of an instruction included in the first code and outputting two or more instructions of the second code according to the determined operand pattern.
 10. An information processing apparatus comprising: a memory configured to store a table data set that represents mappings between a plurality of operand patterns and a plurality of second instructions, the plurality of operand patterns indicating types of operands possibly included in a first instruction used in a first assembly language, the plurality of second instructions being used in a second assembly language or a machine language corresponding to the second assembly language, the table data set mapping two or more of the plurality of second instructions to each of the plurality of operand patterns, the plurality of operand patterns including a first operand pattern and a second operand pattern, the first operand pattern designating a first register having a first bit length, the second operand pattern designating a second register having a second bit length different from the first bit length; and a processor configured to execute a process including generating, based on the table data set, a translation program used to translate first code written in the first assembly language into second code written in the second assembly language or the machine language, the translation program defining a process of determining an operand pattern of an instruction included in the first code and outputting two or more instructions of the second code according to the determined operand pattern. 